Royal Enfield Queries

This is a discussion on Royal Enfield Queries within Motorbikes, part of the BHP India category; Originally Posted by The_Mad_Hatter
For a CI Bullet, would it be best to have a 1000 km interval between oil ...

For a CI Bullet, would it be best to have a 1000 km interval between oil top-ups? I'm pretty sure the oil change interval is 3000 km, but since the old CIs are not as efficient with oil circulation as the newer ones, I was just wondering if a 1000 km top-up interval would be better for the engine.

Unless the engine is not in good state, there is no need to check the oil levels frequently.
If the engine is in good state, you need to check probably once every 1000 kms and top up only if the oil level is dropped below the L mark, by topping up around 100ml.
Normally , the oil level will drop to the L mark around the oil change interval time.
On my CI 350, I top up the oil normally before a ride or when I feel the engine is getting rough. It would be between the L and high and the oil change is done nearing the 5k kms mark. The good thing about CI engines are, the engine gets smoother as the oil gets older, but not too old.

Hi Jim,
When I start, I get blue / black heavy smoke, I can see sooth settling on my palm when placed against smoke.
Now about the spark plug - I hardly ride the bike for a distance of half a kilometer (0.3 miles) and the bike stops. Repeated attempts to kick start miserably fails. This is when I notice the spark plug black in colour with oil (Thar type). Upon cleaning the plug, I can ride for another half a kilometer and this keeps repeating.
The other day the engine back fired followed by engine stopping, moreover the back fire was through the carb. Noticed this as I had removed the rubber hose between carb and air filter. Does this indicate issue at the inlet valve?
By the way, I am the mechanic for my ride . It is said in India that if you have a bullet then you are a mechanic , this is valid for old bikes.
Thanks for you reply,
Venky

Quote:

Originally Posted by ArizonaJim

GrayBerry

I don't think that the backfiring thru the carb has anything to do with your problem although it can damage the rubber hose you mentioned.

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This should be done.

IMO, work in the lower half of the engine should not be needed.

Good luck.

Dear All,
Just opened my engine head and cylinder. Looks like I may have to change my cylinder and piston.
My bike is a 2001 AVL 350 engine. I was told that re-boring cannot be done and I will have to purchase a new cylinder (not sure if these cylinders are manufactured these days).
However, one of the mechanic suggested to go the Cast Iron way. Any suggestions?
If I need to do that, then I will need a new crank, connecting rod, piston, cylinder and head unit. I was also told it may not be a direct drop in fit and will need some work on a lathe. Has anyone done this before and is it worth going this way?
Venky

Dear All,
Just opened my engine head and cylinder. Looks like I may have to change my cylinder and piston.
My bike is a 2001 AVL 350 engine. I was told that re-boring cannot be done and I will have to purchase a new cylinder (not sure if these cylinders are manufactured these days).
However, one of the mechanic suggested to go the Cast Iron way. Any suggestions?
If I need to do that, then I will need a new crank, connecting rod, piston, cylinder and head unit. I was also told it may not be a direct drop in fit and will need some work on a lathe. Has anyone done this before and is it worth going this way?
Venky

I am not sure why you were told the cylinder can't be rebored but first a few comments about cylinders and the need to rebore them.

IMO, there are only two reasons a cylinder needs to be rebored.

•If there are relatively deep longitudinal scratches that run down the cylinder wall such as something that might be caused by a loose snap ring or gudgeon (wrist) pin the cylinder may need reboring. These scratches will be very obvious to anyone looking at the bore.

•If there is taper in the bore where the upper area is 0.02 mm larger than the lower area of the cylinder a rebore is suggested. If the upper area is 0.25 mm larger, a rebore is required.

Just looking at the bore and saying something like "it's glazed" is not a reason to rebore.

If the cylinder doesn't have the scratches or taper I mentioned, usually the surface can be lightly honed to create tiny scratches in the surface, new piston rings installed and the engine put back together and it will be fine.

This honing process can even be done with some medium grit sandpaper.
To do it, the thing to remember is you are trying to make very small grooves which will hold oil to lubricate the new piston rings while they break in.
When doing it the sandpaper is rotated about 180° as it travels from the top of the bore to the bottom.
The rotation is then reversed on the next stroke down the bore so it creates a cross hatched pattern.
This will serve nicely for breaking in the new piston rings.

There is also no need to replace the piston unless it is showing signs of excessive wear. This is usually most pronounced on the lower piston skirt.
The piston ring grooves can usually be cleaned up nicely for the new piston rings. In fact, a tool is available for cleaning out the hardened carbon in the bottom of the grooves and with this tool it is a 3 minute job. (The width of the grooves should not be increased so some care is needed when doing this job.)

With a bore with no scratches or wear, new piston rings are all that are needed IMO.

If the cylinder does need reboring, unless it has been rebored at least twice in the past, it should be able to be rebored again.

Pistons and piston rings are usually supplied (generally speaking) in increments of 0.5 mm and a cylinder should easily have enough material for at least two reborings. (The first, 0,5 mm oversize, the second, 1.0 mm oversize.).
Actually there should be enough steel cylinder wall for a third, 1.5mm oversize boring but there may not be any pistons or rings available in that size.

Now, about the cast iron cylinders.
IMO, you should avoid them unless they are the last possible answer to the engines problems.

The steel lined aluminum cylinders remove heat from the bore and piston three times faster (better) than cast iron.

One of the prime problems with the old cast iron cylinders is they cause the engine to overheat and often seize the piston if they are run hard.

If you change the cylinder to a cast iron one you will not be able to utilize the power and speed your AVL has been able to give and engine failure can become a real possibility.
Of course if you always just putt, putt down the road this may not be a problem but if you are using the engines power often or riding at fairly fast speeds this problem is worth thinking about.

There are those who may disagree with me and that's fine but just remember, there are also mechanics who make their money by selling services that are not needed like, selling a total rebore+new piston/+new piston rings rather than just replacing the worn out piston rings.

Finally, reguardless of what you end up doing, don't forget to also have the intake valve and exhaust valve lightly lapped with their respective valve seats.
(Unless the valve head has cracks in the edges of its head, it should not need replacing.)

If the existing cylinder is truly in need of reboring and it has been rebored to its maximum limits, another possible solution exists to make the existing cylinder usable.

It won't be inexpensive and it will need the services of a good machine shop with precision machines and a good oven.

The existing aluminum cylinder has a steel sleeve pressed into it.
If the existing sleeve is removed and a new steel sleeve is fabricated and installed, it can be bored to a size that is compatible with a new, stock piston.

As aluminum has a higher coefficient of thermal expansion than steel, heating the assembly will cause the aluminum to increase in size faster than the steel sleeve.
(The coefficient of thermal expansion is the amount a material grows or shrinks with a change in temperature*).

If the existing cylinder were heated to a temperature of 232°-260°C (450°-500°F) and allowed to bake at that temperature for at least 1/2 hour for complete stabilization, the steel sleeve could easily be pressed out of the aluminum housing. (A good stable support to support the flange on the cylinder would be needed to prevent damage to the now, softened aluminum.)

With the existing steel liner removed the outside diameter, length and sizes of any other important features needs to be determined to an accuracy of at least 0.025mm (.001 inch) or better.

A suitable carbon steel tube would then need to be purchased.
It does not need to be a hardenable steel so a low carbon tube will be fine.
(IMO, the unmachined tube should have at least 2 mm of material on its external and internal surfaces.)

The exterior and the length of this tube should be machined to match the existing, old sleeve to an accuracy of 0.025 mm (.001 inch).
The bore of the tube can be machined providing at least 0.40 mm (.016 inch) is left in it.

After heating the aluminum cylinder to 230°-260°C (446°-500°F), leaving the new sleeve at room temperature or chilling it before assembly will usually allow the steel sleeve to fall into place. Then, the entire assembly allowed to air cool slowly.

With the sleeve installed, it can now be machined to the finish bore size required by the piston. (I recommend boring the sleeve to at least 0.152 mm (.006 inch) larger than the maximum diameter of the piston but your local mechanic may choose a different size difference. By the way, the cylinder bore is larger than the piston to provide clearance for the aluminum pistons growth as it heats up. This is the same coefficient of thermal expansion as I mentioned above is working here every time the engine is started.)

Properly done, your rebuilt cylinder should be as good as new.

* The Coefficient of Thermal Expansion for a typical cast aluminum is around 13 X 10^-6 inches per degree F per inch length.
The Coefficient of Thermal Expansion for a typical steel is around 8 X 10^-6 inches per degree F per inch length.

The difference in size of a 3 inch diameter interface of a aluminum/steel assembly at 475°F temperature will be about .0086 inches. (0.217 mm) which is about the amount of a typical press fit.
As there may be a greater press fit in the Royal Enfields cylinder the use of a press may be needed to force the steel sleeve out of or in to the aluminum housing.

you need to check probably once every 1000 kms and top up only if the oil level is dropped below the L mark, by topping up around 100ml. Normally , the oil level will drop to the L mark around the oil change interval time.

Sorry for the noob question, but how to check the oil level? I tried looking from that small circular window they provide but I can't see anything. Used a torch also, cleaned it a bit as well. Do I have to use a dipper stick?

Sorry for the noob question, but how to check the oil level? I tried looking from that small circular window they provide but I can't see anything. Used a torch also, cleaned it a bit as well. Do I have to use a dipper stick?

The first few posts on the below link will provide information on checking oil level through the sight glass.

He is looking at changing the exhaust mainly for sound and performance and looks is second option.

Please help

If it is sound, I would suggest going for the stock replacement muffler that is available from Royal Enfield itself. All the after markets now are just too loud and annoying.
Performance hikes from these exhausts are marketing gimmicks mainly. They really do not bump the bhp and the feel you get after changing is mainly because of the sound and a bit of free flow from the fully restricted stock muffler. Otherwise, you get better torque from the stock one itself.
Red Rooster's exhaust is good and will increase the bhp provided you mod or change other related parts. If its just sound, go for a normal short bottle muffler which is available from RE as well as the local parts shop.

guys, I own a classic 350 which has done about 2800 kms now. Yesterday evening after coming out from a movie I started the bike using the electric start - starting was fine - but the moment I engaged the first gear some loud metallic clatter (it was more of a metal breaking noise) came from the engine area. It was so loud that my cousin who was standing some 20 feet away came running asking whether something broke.

but, the bike rode normally after that all the way home - some 20 kms. And today too, there wasnt any drama like yesterday.

guys, I own a classic 350 which has done about 2800 kms now. Yesterday evening after coming out from a movie I started the bike using the electric start - starting was fine - but the moment I engaged the first gear some loud metallic clatter (it was more of a metal breaking noise) came from the engine area. It was so loud that my cousin who was standing some 20 feet away came running asking whether something broke.

but, the bike rode normally after that all the way home - some 20 kms. And today too, there wasnt any drama like yesterday.

any ideas about that big metal breaking sound?

Most probably the clutch plates might not have disengaged properly (Cold climate- thick oil-sticky clutch plates). If that was the case, what you heard is the dogs in the gear grinding against one another. Always make a habit of freeing the clutch plates by pulling in the clutch lever and using the kicker till the plates free themselves. Start the motorcycle only after that. It will prevent the motorcycle from grinding into gear and keep yourself from spending for costly repairs.

Could be the sound from sprag clutch slipping. Check if the sound is appearing only while using the electric starter.

[EDIT] Just noticed that the sound is coming when you engage the first gear and not while cranking. Sorry for that! Try disengaging the clutch as Adrian suggested and check if the clutch is adjusted properly.

Leaving the ignition off while freeing the clutch plates would be the right way to do it.

With the clutch lever pulled in and while you are depressing the kick starter the crankshaft will start to turn.
As soon as it comes to the compression stroke the increased resistance to movement will cause the multiple clutch disks to loose their grip on the neighboring clutch plates and it will begin to slip.
When this happens, the kick start lever will suddenly be easy to push down.

As your engine never goes thru the compression stroke it won't try to start or to kick back.
Your leg should be fine after doing this.

I'm planning to buy the Classic 500. I would want to know the maintenance costs as I heard stories of brake pad, clutch wire replacements and the likes once every 2-3 months. One guy who owns the Classic 350 also confirmed this. How much of a concern is this, if true?

Just want to now how much would it cost to run and maintain Classic 500. I just need an heads up on what to expect before I take the plunge.